let N be non empty with_non-empty_elements set ; for S being non empty stored-program IC-Ins-separated definite realistic halting steady-programmed weakly_standard AMI-Struct of N holds (il. S,0 ) .--> (halt S) is closed
let S be non empty stored-program IC-Ins-separated definite realistic halting steady-programmed weakly_standard AMI-Struct of N; (il. S,0 ) .--> (halt S) is closed
reconsider F = (il. S,0 ) .--> (halt S) as NAT -defined the Instructions of S -valued FinPartState of ;
let l be Element of NAT ; AMISTD_1:def 17 ( not l in proj1 ((il. S,0 ) .--> (halt S)) or NIC (((il. S,0 ) .--> (halt S)) /. l),l c= proj1 ((il. S,0 ) .--> (halt S)) )
assume A1:
l in dom ((il. S,0 ) .--> (halt S))
; NIC (((il. S,0 ) .--> (halt S)) /. l),l c= proj1 ((il. S,0 ) .--> (halt S))
A2:
dom F = {(il. S,0 )}
by FUNCOP_1:19;
then A3:
l = il. S,0
by A1, TARSKI:def 1;
F /. l =
F . l
by A1, PARTFUN1:def 8
.=
halt S
by A3, FUNCOP_1:87
;
hence
NIC (((il. S,0 ) .--> (halt S)) /. l),l c= proj1 ((il. S,0 ) .--> (halt S))
by A2, A3, AMISTD_1:15; verum